3-(Hydroxyhydrocarbylsecondaryamino)thiophene 1,1-dioxides and polyurethanes chain extended therewith

ABSTRACT

Chain extended polyurethanes are prepared, using certain 3(hydroxyhydrocarbylsecondaryamino)thiophene 1,1-dioxides, some of which are new chemicals. E.g., 3-(2hydroxypropylamino)tetrahydrothiophene 1,1-dioxide is especially useful as a chain extender for high resiliency, flexible polyurethane foams.

United States Patent [1 1 Mao [ June 3, 1975 3-(HYDROXYHYDROCARBYLSECON- DARYAMINO)THIOPHENE 1,1-DIOXIDES AND POLYURETHANES CHAIN EXTENDED THEREWITI-I {75] Inventor: Chung-Ling Mao, Sandy Hook,

Conn.

[73] Assignee: Uniroyal, Inc., New York, NY.

[22] Filed: Jan. 18, 1974 [21] App]. No.2 434,470

3.821.132 6/1974 Mao 260/25 AM 3,823,096 7/l974 Fabris 260/25 AM 3,826,763 7/1974 Lamplug 260/25 AM FOREIGN PATENTS OR APPLICATIONS 242,766 l/l963 Australia 260/25 AM 574,6ll 4/1959 Canada 260/25 AM Primary ExaminerDonald E. Czaja Assistant ExaminerC. Warren Ivy Attorney, Agent, or Firm-James J. Long 5 7 ABSTRACT Chain extended polyurethanes are prepared, using certain 3-(hydroxyhydrocarbylsecondaryamino)thiophene l,l-dioxides, some of which are new chemicals. E.g., 3-(2-hydroxypropylamino)tetrahydrothiophene l,l-di0xide is especially useful as a chain extender for high resiliency, flexible polyurethane foams.

35 Claims, No Drawings 1 3-(HYDROXYHYDROCARBYLSECON- DARYAMINO)THIOPHENE 1,1-DIOXIDES AND POLYURETHANES CHAIN EXTENDED THEREWITH This invention relates to chain-extended polyurethanes, a method of making same, and certain new chain extenders useful in said method.

US. Pat. No. 2,460,955, Mortenson, Feb. 8, 1949, discloses a mixture, described as useful as a plasticizer for polyvinyl alcohol, and presumed to include 3-(2- hydroxyethylamino)thiolane-l ,l-dioxide. The latter may also be called, according to the nomenclature used herein. 3-(2-hydroxyethylamino)tetrahydrothiophene l,l dioxide, and would have the formula:

The foregoing chemical is a homolog of certain chemicals of the present invention, but is not taught as useful for chain-extending polyurethanes.

US. Pat. No. 3,093,793, Loev, July 23, I963, discloses certain sulfolane solvents for pharmaceutical compositions. The chemicals of Loev are not taught as useful for chain-extending polyurethanes; the specific chemicals shown are not bifunctional and therefore would not function as chain extenders, unlike the bifunctional chemicals of the present invention.

A In the manufacture of polyurethanes (long chain polyol-polyisocyanate reaction products) it is of course conventional to employ a chain extender" which is ordinarily a poly-functional organic compound having two or more reactive hydrogen atoms (reactive toward isocyanate; as determined by what is known as the Zerewitinoff method) as an aid in building up a polyurethane molecular structure having desirable properties. In practice, the requirements of a chain extender can be quite complex and exacting, and unfortunately many of the conventional ones suffer from various shortcomings in at least certain respects. One widely used chain extender is carcinogenic. To obviate this and other disadvantages there has accordingly been a continuing search by those skilled in the art for new chain extending agents.

In accordance with the invention chain extended polyurethanes are prepared using as the chain extend' ing agent a 3-(hydroxyhydrocarbylsecondaryamino)- thiophene l,l-dioxide of the following formulas l or ll:

Formula I wherein X may be hydrogen, an alkyl group having I to 5 carbon atoms or a halogen atom,

Y may be hydrogen, an alkyl group having 1 to 5 carbon atoms, or an aryl group,

2 may be hydrogen, an alkyl group having I to 5 carbon atoms, an aryl group or a halogen atom,

R may be (1) an open chain aliphatic group having 2 to 10 carbon atoms, (2) an open chain aliphatic group having 2 to l0 carbon atoms substituted with one or more aryl groups, or (3) a cycloaliphatic group having 4 to 8 carbon atoms,

the hydroxyl group being attached to a carbon atom of R that is separated from the secondary amino nitrogen atom by at least one carbon atom;

Formula II wherein X may be as defined in formula I, R may be l an open chain aliphatic group having 2 to 10 carbon atoms, (2) an open chain aliphatic group having 2 to [0 carbon atoms substituted with one or more aryl groups, or (3) a cycloaliphatic group having 4 to 8 carbon atoms, the hydroxyl group being attached to a carbon atom of R that is separated from the secondary amino nitrogen atom by at least one carbon atom, and

R, R R and R may be the same or different and may be hydrogen, an alkyl group having l to 5 carbon atoms, or halogen.

Certain of the foregoing 3- (hydroxyhydrocarbylsecondaryamino)thiophene l l dioxides are new chemicals, namely, those of Formula I further embodying the proviso that when R is the group then at least one of X, Y or Z must be other than hydrogen. and those of Formula II.

The heterocyclic (hydroxyhydrocarbylsecondaryamino)thiophene dioxides of the foregoing formulas are surprisingly useful as chain extenders for polyurethanes and specifically for polyurethane foams which unexpectedly exhibit a unique combination of physical properties such as high tensile strength, high tear resistence, high elongation, good resilient properties and low compression setv The chemicals represented by Formula I, that is. the 3 hydroxyhydrocarbylsecondaryamino )tetrahydrothiophene l,l-dioxides, find their greatest utility specifi cally in making polyurethane foam by the so-called one-shot" method, while the chemicals represented by Formula II. that is, the 3-(hydroxyhydrocarbylsecondaryamino) dihydrobenzoIblthiophene l,l dioxides. are useful not only in making one-shot foams. but also in making solid polyurethane elastomers and thermoplastics, for example from castable prepolymers, as well as coatings, etc.

The chain extending agents having Formula I may be made by a onestep synthesis starting with the known 4.5dihydrothiophene l.l-dioxides Ill according to the following scheme (wherein the symbols have the meanings previously assigned):

(hydroxyhydrocarbylsecondaryamino)tetrahydrothiophene 1,1-dioxides I are formed by reacting a 4,5-dihydrothiophene l,l-dioxide III with the appropriate monohydroxyhydrocarbylamine IV in a suitable solvent.

Similarly. the 3- (hydroxyhydrocarbylsecondaryamino)-2,3- dihydrobenzolb]thiophene l.l-dioxide chain extenders ha ing Formula II may be made by reacting a known benzo-[blthiophene dioxide V with an appropriate monohydroxyhydrocarbylamine VI in a suitable solvent according to the following scheme (the symbols being as previously defined):

In general, one mole of the thiophene dioxide is reacted with 1.] moles of the monohydroxyhydrocarbylamine. The reaction temperature is generally kept at 30l 20 C. and the reaction times will vary from two to twentyfour hours depending upon the thiophene dioxide and the amine employed. The reaction solvents used in this reaction are water, alcohol-water mixtures and alcohols. Examples of alcohols that may be employed include methanol, ethanol, propanol, isopropanol, pentanol, hexanol and cyclohexanol. The monohydroxyhydrocarbylamines themselves may also be used as solvents as for example, ethanolamine, propanolamine, butanolamine, hexanolamine and the likev Any of the 4,5-dihydrothiophene l,1-di0xides having the following general formula may be used as the starting material III for making the tetrahydrothiophene l,l-dioxides (wherein the symbols are as defined above):

III

Exemplary of such thiophene dioxides are 4.5-dihydrothiophene l,l-dioxide. 2-methyl-4 5-dihydrothiophene l,l-dioxide, 2-chloro-4,5-dihydrothiophene l,ldioxide 2-bromo-4.Sdihydrothiophene l.l-dioxide, 2 5-dimethyl4 5-dihydrothiophene l,1-dioxide, 2-ethyl-4.5-dihydrothiophene l,l-dioxide, 2-chloro-4 dibromo-2,3-dihydrobenzo[blthiophene and the like.

A preferred subclass of chain extenders of Formula I are those in which X, Y and Z are hydrogen, and R is an open chain alkylene group having 2 to ID, preferably 3 to ID, carbom atoms. Particularly preferred compounds of this subclass are 3-( 2- hyd roxypropylamino )tetrahydrothiophene l, I -dioxide, 3 3-hyd roxypropylamino )tetrahydrothiophene l, l dioxide, 3 o-hydroxyhexylamino )tetrahydrothiophene l,l-dioxide, and 3-( Z-hydroxy-l l dimethylethylamino) tetrahydrothiophene l, -dioxide.

Another preferred subclass of compounds of Formula l are those in which Y and Z are hydrogen, X is a halogen atom (e.g., chlorine, bromine) and R is an open chain alkylene group having 2 to ID carbon atoms. Particularly preferred in this subclass are 2- chloro-2-(2-hydroxypropylamino)tetrahydrothiophene l, l -dioxide, 2-bromo-3-( Z-hydroxethylamino)tetrahydrothiophene l,l-dioxide, and 2-bromo-3-( 2- hydroxypropylamino)tetrahydrothiophene l,l-dioxide.

Still another preferred subclass of compounds of Formula l are those in which X, Y and Z are hydrogen, and R is an open chain alkylene group having 2 to ID carbon atoms substituted with a phenyl group. Particularly preferred in this subclass is 3-(2-hydroxy-2- phenylethylamino) tetrahydrothiophene l,l-dioxide.

Yet another preferred subclass of compounds of For mula l is represented by those in which X, Y and Z are hydrogen and R is a cycloalkylene group having 4 to 8 carbon atoms. Particularly preferred in this subclass is 3-( 4-hydroxycyclohexylamino)tetrahydrothiophene l,l -dioxide.

A preferred subclass of chain extending agents of Formula II are those in which R, R R, R and X are hydrogen and R, is an open chain alkylene group having 2 to l carbon atoms. Particularly preferred members of this subclass are 3-(2-hydroxypropylamino)- 2,3-dihyd robenzol blthiophene l, l -dioxide, 3-(2- hydroxyethylamino)-2,3-dihydrobenzo[blthiophene |,l -dioxide and 3-( G-hydroxyhexyamino )-2,3- dihydrobenzo[b]thiophene l, l-dioxide.

Another preferred subclass of chemicals of Formula II are those in which R, R, R, R and X are hydrogen, and R, is an open chain alkylene group having 2 to l0 carbon atoms substituted with a phenyl group. A particularly preferred chemical in this subclass is 3-(2- hydroxy-Z-phenylethylamino)-2,3-dihydrobenzo[b]- thiophene l,l-dioxide.

To employ the present compounds as chain extending agents for polyurethanes the compounds may simply be substituted at least in part for the conventional chain extending agents in any conventional polyurethane formulation of the kind ordinarily employing a chain extender. The proportions of the present chain extender employed may be the same as in conventional practice and the chain-extending reaction may likewise be carried out under the same conditions as are usually employed in conventional polyurethane chain extension. Polyurethane systems of the so-caled one-shot type, or of the prepolymer type, may be employed, and the final product may be foam (either rigid or flexible) or a solid, whether elastomeric or otherwise, including thermoplastic polyurethanes, polyurethane surface coatings, etc. As is well understood by those skilled in the art, polyurethane forming systems conventionally l, l -dioxide,

LII

involve a combination of at least one long chain polyol (whether 'a polyester polyol, a polyether polyol or a polyhydrocarbon polyol) and at least one organic polyisocyanate, whether a diisocyanate or a polyisocynate of higher functionality, of aliphatic, cycloaliphatic, or aromatic type. The relative proportions of polyol and polyisocyanate. may be as in conventional practice appropriate to the particular kind of final product desired and the processing or fabricating method chosen.

The polyether types of polyols employed in making polyurethanes include, as is well .known to those skilled in the art, poly(oxyalkylene) glycols [c.g. poly (oxyethylene) glycol, poly(oxypropylene) glycol, poly(oxytetramethylene) glycol, etc.] and higher polyether polyols, such as triols e.g. poly(oxypropylene triol), including polyether polyols of higher functionality than three leg, poly(oxypropylene adducts of pentaerythritols) and poly(oxypropy lene adducts of sorbitol)]. Mention may be made of such polyether polyols as poly(oxypr'opylene)-poly(oxyethylene)glycol, poly(oxypropylene) adducts of trimethylol propane, poly(oxypropylene)- poly(oxyethylene)adducts of trimethylolpropane, poly(oxypropylene) adducts of l,2,6-hexan etrio|, poly- (oxypropylene )-poly(oxyethylene) adducts of ethylenediamine, poly(oxypropylene) adducts of ethanol amine, and poly(oxypropylene) adducts of glycerine.

The polyester types of polyols used in making polyi urethanes are likewise well known in the art and require no detailed description here. It will be understood that they include chain extended polyesters made from a glycol (e.g., ethylene and/or propylene glycol) and a saturated dicarboxylic acid (e.g., adipic acid). by way 1 of non-limiting example there may be mentioned poly (ethylene adipate) glycol, poly(propylene adipate) glycol, poly(butylene adipate) glycol, poly(caprolactone) glycol, poly(ethylene adipate-phthalate) glycol, poly- (neope ntyl sebacate) glycol, etc. Small amounts of tri alcohols such as trimethylolpropane or trimethylolethan e' may be included in the polyester preparation. Polyester polyols with functionalities of three or more [e.g., glycerides of l2-hydroxystearic acid] are also useful. Suitable polyester polyols include those obtainable by reacting such polyols as 1,4-butanediol, hydroquinone bis(2-hydroxyethyl)ether, ethylene glycol, di-

ethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 2-methyl-2-ethyl-l,3propanediol, 2-ethyll ,3-hexanediol, 1,5-pentanediol, thiodiglycol.

l,3-propanediol, l,3-butanediol, 2,3-butanediol, neo- 1 pentyl glycol, l,Z-dimethyl-l,2-cyclopentanediol, l,2-

The above polyols typically have a molecular weight of about l80 to 8000.

Conventional polyisocyanates used in polyurethane manufacture include. as is well known, aliphatic polyisocyanates, whether open chain, cycloaliphatic or araliphatic, Examples of aliphatic polyisocyanates conventionally employed are trimethylene diisocyanate, tetramethylene-l,4-diisocyanate, hexamethylene- 1,6- diisocyanate, l-methyl-2,4-and l rnethyl-2,6- diisocyanatocyclohexane and mixtures thereof, pxylylene diisocyanate and m-xylelene diisocyanate (XDI) and mixtures thereof, 4,4'-diisocyanatodicyclohexylmethane, isophorone diisocyante, 2,2,4- and 2,4,4-trimethylhexamethylene diisocyanate, and the like.

Simiarly, the aromatic polyisocyanates are suitable and include, by way of non-limiting example, such bod ies as 2,4-toluene diisocyanate and 2,6-toluene diisocyanate and mixtures thereof (TDl, including crude and polymeric forms), 4,4' diphenylmethane diisocyanate (MDl, including crude and polymeric forms), pphenylene diisocyanate, 2,4,6-tolyene triisocyanate, 4,4'4"-triphenylmethane triisocyanate, 2,2-bis(pisocyanato-phenyl)-propane, polymeric methylene bis(phenyl-4-isocyanate) (e.g., PAPI), naphthalene- 1,5-diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, 3,3'-dimethoxy-4,4-biphenylene diisocyanate, 3,3'-diphenyl-4,4'-biphenylene diisocyanate, 4,4'-biphenylene diisocyanate, 3,3'-dich1oro-4,4'- biphenylene diisocyanate, and the like. Mixures of two or more of such diisocyanates may also be used. Triisocyanates typically obtained by the reaction of 3 moles of an arylene diisocyanate with 1 mole of triol for example, the reaction product formed from 3 moles of tolylene diisocyanate and 1 mole of hexanetriol or of trimethylol propane, may be employed.

In one important aspect, the invention is directed to an improved flexible resilient polyurethane foam and method of making the same, employing the new chemicals described herein as chain extenders. Thus, it is well known that polyetherpolyolpolyisocyanate foams can be made by reacting a non-linear slightly branched polyether glycol or polyol, a diisocyanate, and a polyfunctional chain extender. The present invention is based in part on the discovery that polyurethane foam having a remarkable combination of desirable physical properties surprisingly results when the new, N,N'- bis( l ,l-dioxohydrothienyl)-diaminoalkanes are employed as bifunctional chain extenders. The foams of this invention are characterized by high tensile strength, high tear resistance and low compression set, This unique combination of physical properties is largely determined by the unique chain extenders employed.

Formation of the preferred foamed products of this invention may be accomplished in a one-shot system by reacting the polyol with excess polyfunctional isocyanate and the new chain extender of the invention in the presence of water and cell modifying agents, e.g. sili cone such as trimethyl end-blocked dimethyl polysiloxanes. The polyfunctional isocyanate is typically present in amount of 5300%, say 40% by weight of the polyol. The binary chain extender of the invention is frequently present in the one shot foam formulation in amount of 0.5 to preferably l to 10%, by weight ofthe polyol. The water is employed in amount to react with the isocyanate to liberate sufficient gas (carbon dioxide) to produce a foam of the desired physical characteristics. From 0.6 to 10%, say 4% water (by weight of polyol) will give good results.

The mixing of the constituents in the one-shot system is typically performed at room temperature. The polyol, chain extender of the invention, catalyst, water, flame retardant and other cell-modifying agents (surface active agents) such as trimethyl end-blocked di methyl polysiloxanes are first and then the polyisocyanate is added with vigorous stirring. The gas forming reaction, the chain extension and the cross linking reactions start simultaneously when the polyisocyanate is added.

Some examples of useful catalysts are N-methylmorpholine, N-ethyl-morpholine, triethyl amine, triethylene diamine (Dabco), N,N'-bis(2-hydroxylpropyll-2- methyl piperazine, diamethyl ethanol amine, tertiary amino alcohols, tertiary ester amines and the like.

In addition to or in place of water the formulation may include a blowing agent of the kind conventionally employed in making polyurethane foam, usually a vola tile organic liquid (e.g. boiling within the range of from 50 to l50F) such as pentane, trichlorofluoromethane, trichloromethylene, tetrachloroethylene, trichlorotrifluoroethane, trichloroethane, methylene chloride, di bromotetrafluoroethane, carbon tetrachloride, etc.

The resulting one-shot foams of the invention surprisingly are characterized by a unique combination of physical properties such as high tensile strength, high tear resistance, high elongation, good resilience properties and low compression set. These flexible foams find utility as automobile and furniture cushioning materials, pillows, mattresses and carpet underlays.

Another important form of the invention is concerned with solid polyurethanes, particularly those made by the so-called prepolymer technique wherein the polyol is prereacted with an excess ofthe polyisocyanate, and thereafter the prepolymer is chain-extended or cured, using the bifunctional chain extending agent of the invention. Using liquid prepolymers cast elastomeric (or thermoplastic) articles and coatings having highly useful properties may be made in this way.

The following examples demonstrate the invention.

EXAMPLE I 4 hours. The solvent and the excess 2- hydroxypropylamine were removed under a reduced pressure. The product, 3-(2 hydroxypropylamine )tetrahydrothiophene l,l-dioxide obtained was a viscous liquid that became a solid, mp. 50-60C. IR spectrum showed absorptions at 3500 cm (OH), at 3300 cm (NH), at 1310 cm and H25 cm(SO and at 1080 cm* (C-O).

Analysis for C H NO S (percent):

CalcD: C, 43.50; H, 7.82; N, 7.25; S, l6,59.

Found: C, 43.32; H, 7.75; N, 7.01; S, 16.39.

EXAMPLE 2 Example 1 was repeated using the thiophene dioxide of Example 1 and substituting 3hydroxypropylamine for Z-hydroxypropylamine. The resultant product. 3 (3-hydroxypropylamino )-tetrahydrothiophene 1.1- dioxide. was a viscous liquid that became a solid on standing. mp. 55-60 C. IR spectrum showed the absorption bands at 3500 Cm (01-1 1. at 3300 cm (NH). at 1300 cm and 1130 cm' (S and at 1070 cm C-O- 1.

Analysis for C H NO tpercent):

Calc'd: N. 7.25; S. 16.59.

Found. N. 7.24; S. 15.90.

EXAMPLE 3 Example 1 was repeated using the dioxide of Example 1 and substituting o-hydroxyhexylamine for 2- hydroxypropylamine. The resultant product. 3-( 6- hydroxyhexylamino) tetrahydrothiophene 1.1-dioxide was a viscous liquid and was hygroscopic. The nmr spectrum in CDC] showed bands with relative areas in agreement with the structure. The 1R spectrum showed absorption at 3520 cm (OH). at 3300 cm" (NH). at 1310 cm and 1150 cm (50 and at 1050 cm C--() 1.

Analysis for C H NO S (percent):

Calcd: C. 51.03; H. 8.99: N. 5.95; 13.62.

Found: C. 49.75: H. 8.87; N. 5.82; 13.39.

EXAMPLE 4 Example 4 Example 1 was repeated using the thiophene dioxide of Example 1 but substituting 2-hydroxymethyl-2- propylamine for 2-hydroxypropylamine. The resultant product. 3-(2-hydroxy-l .1 dimethylethylamino)tetrahydrothiophene 1.1-dioxide was a viscous liquid which became solid on standing. mp 90-95C. after one recrytallization from a 90/10 volume percent toluene-ethanol solvent mixture. The IR spectrum showed bands at 3500 cm" (OH). at 3300 cm" (NH). at 1315 cm" and 1140 cm (SO- and at 1060 cm (CO). The NMR spectrum showed the bands with relative areas in agreement with the structure.

Analysis for C,.H NO S (percent):

Ca1c'd:(.46.35; H. 8.26; N. 6.75; S. 15.46.

Found: C. 45.57; H. 8.14: N. 6.60; S. 1548.

EXAMPLE 5 Example 1 was repeated using the thiopene dioxide of Example 1 and substituting (2'hydroxy-2- phenyhcthylamine for 2-hydroxypropylamine. The re sultant product 3( 2hydroxy-2- phenylethylamino)tetrahydrothiopene. l .1dioxide was a viscous liquid which became solid on standing. and had a melting point of 1 1 10 C after one recrystallization from hot toluene. The 1R spectrum showed the absorption bands at 3500 Cm"(OH). at 3300 cm"(NH). at 1310cm" and 1030 cm(SO at 1060 cm (C 0). and at 765 cm and 708 cm (monosubstituted aromatic). The Nmr spectrum was in agreement with the structure.

Analysis for C H NO S (percent): Calcd: C. 56.45; H. 6.71; N. 5.49; 8. 12.55. Found: C. 56.60; H. 6.54; N. 5.60; S. 2.53.

EXAMPLE 6 Example 1 was repeated using the thiopene dioxide of Example 1 and substituting 4-hydroxycyclohexylamine for 2-hydroxypropyiaminc. The resultant product. 3-(4-hydroxycyclohexylamino)tetrahydrothiophene 1.1-dioxide was obtained as white needles. mp. 168-171C after one recrystallization from a /10 volume percent toluene-ethanol solvent mixture.

Analysis for C H NO S (percent):

Calcd: C. 51.48; H. 8.27; N. 6.00; S. 13.74.

Found: C. 51.49; H. 8.10; N. 6.06; s. 13.15.

EXAMPLE 7 Example 1 was repeated using the alkanolamine of Example 1 (Z-hydroxypropylamine) but substituting 2-chloro-4.S-dihydrothiophene 1.1-dioxide for the di oxide. The resultant product. 2-chloro-3-(2- hydroxypropylamine )tetrahydrothiophene 1.1-dioxide was a viscous liquid. The IR spectrum showed bands at 3510 cm (OH). at 3310 cm (NH). at 1320 cm and 1130 cm (S0 and at 1050 cm (CO).

Analysis for C H ClNO S (percent):

Ca1cd:Cl. 15.57; S. 14.08.

Found: Cl. 15.80; S. 1457.

EXAMPLE 8 EXAMPLE 9 Example 8 was repeated using the thiophene dioxide of Example 8 but substituting 2-hydroxypropylamine for Z-hydroxyethylamine. The resultant product. 2- bromo-3-(Z-hydroxypropylamino)tetrahydrothiophene 1,1-dioxide was a viscous liquid. The IR showed absorptions at 3500 cm (OH). at 3310 cm (NH). at 1320 cm and 1125 cm (S0 and at 1050 cm (CO).

Analysis for C H BrNO S (percent):

Calcd: C. 30.89; H. 5.19; Br. 29.36; N. 5.14; S. 1 1.78.

Found: C. 30.99. H. 5.34. Br. 28.72; N. 5.19; S. l 1.91.

EXAMPLE 10 Example 8 was repeated using 2-hydroxyethylamine EXAMPLE 1 1 Example was repeated using the thiophene dioxide of Example 10 and substituting 2- hydroxypropylamine for 2-hydroxyethylamine. The resultant product. 3-(2-hydroxypropylamino)-2.3- dihydrobenzo[b]thiophene l.l-dioxide was a viscous liquid. The IR spectrum showed absorptions at 3510 cm (OH), at 3310 cm and 1120 cm (S0 at 1060 cm' (C--O) and at 800 cm and 765 cm (aromatic).

Analysis for C,,H NO S (percent):

Calc'd: C, 54.75; H, 6.25; N. 5.80: S, 13.29.

Found: C, 54.69; H, 6.32; N, 5.72; S, 13.09.

EXAMPLE 12 Example 10 was repeated using thiophene dioxide of Example 10 and substituting 6-hydroxyhexylamine for 2-hydroxyethylamine. The resultant product 3-(6- hydroxy-hexylamino)-2,3-dihydrobenzo[blthiophene, 1,1-dioxide was a viscous liquid. The 1R spectrum showed bands at 3500 cm (OH at 3300 cm (NH). at 1300 cm and 1125 cm (50 at 1055 cm (CO) and at 880 cm" and 765 cm (aromatic).

Analysis for C H NO S (percent):

Calcd'. C, 59.33; H, 7.47; N. 4.94; S, 11.31.

Found: C, 59.47; H, 7.49; N, 5.06; S, 10.54.

EXAMPLE [3 Example 10 was repeated using the thiophene dioxide of Example 10 and substituting (2-hydroxy-2- phenyl)ethylamine for Z-hydroxyethylamine. The resultant product, 3-(Z-hydroxy-2-phenylethylamino)- 2.3dihydrobenzo[ b ]thiophene l, l dioxide obtained as white solid had a melting point 123126C. The IR spectrum showed absorptions at 3500 cm (OH), at 3320 cm (NH), at 1310 cm and 1110 em (80:), at 1060 cm" (C-O) and at 770 em and 704 cm*' (aromatic).

Analysis for C H NO S (percent):

Calcd: C, 63.33; H, 5.65; N. 4.61; S. 10.56.

Found: C, 63.07; H, 5.41; N, 4.34; S, 10.58.

As indicated above. chain extenders of this invention find use in the one-shot system of solid foamed polyurethanes. In this system, the mixing of the constituents is typically performed at room temperatures. The polyol (polyester polyol, polyether polyol or polyhydrocarbon polyol), chain extender, catalyst, water. flame retardant and other cell-modifying agents (surface active agents). are first mixed and then the polyisocyanate is added with vigorous stirring. The gas forming reaction, the chain extension and the cross-linking reactions start simultaneously when the polyisocyanate is added.

The formation of foamed products is accomplished in the one-shot system by reacting the polyol with a slight excess. typically about 5 to 10 equivalent weight percent excess. of polyfunctional isocyanate in the presence of water and cell modifying agents. eg. silicones such as trimethyl end-blocked dimethyl polysiloxanes. The polyfunctional isocyanate is typically present in amount of 5300%, say 4092, by weight of the polyol. The water should be present in amount to react with the isocyanate to liberate sufficient gas (carbon dioxide) to produce a foam of the desired physical characteristics. From 0.5 to 10%. say 3% water (by weight of polyol will give good results. Some examples of useful catalysts are N-methylmorpholine, N-ethylmorpholine, triethyl amine, triethylene diamine (Dabco, trademark), N.N'-bis(2-hydroxypropyl)'2-methy1 piperazine, dimethyl ethanol amine, tertiary amino alcohols, tertiary ester amines and the like. For further details on the formulation of polyether-polyol based one shot foam formulations reference may be had to eopending application Ser. No. 336,842 of Mao and Bakker. filed Feb. 28. 1973 now US. Pat. No. 3.82.1,132. the disclosure of which is hereby incorporated herein by reference. An example of this form of the invention is as fol lows:

EXAMPLE 14 This example demonstrates the use of two novel compounds of this invention as binary chain extenders in the preparation of foamed polyurethane structures using a conventional high resiliency foam formulation. For comparison purposes. the most widely used chain extender 4,4'-methylenebis-(o-chloroaniline), which is commonly designated by the code letters MOCA. was also used. The formulations and results are tabulated in Table l.

lt should be noted that the polyurethane foamed structures A and B made with the novel compounds of this invention exhibit a unique combination of physical properties such as high tensile strength, high tear resis tance, high elongation and low compression set. Tensile, tear and elongation in A are superior to C at somewhat higher but still acceptable compression; tear and elongation in B are superior to C at substantially the same compression.

ln Table l the formulations are expressed as parts by weight. The polyol may be a polypropylene glycol triol of 4700 molecular weight made from propylene glycol and endcapped with 20 to ethylene oxide (Voranol 4701; trademark). The Ex. 1 compound is the binary chain extender prepared in Example 1 above; the Ex. 11 compound is that prepared in Example 11 above. The tire retardant may be tris(2,3-

dibromopropyl)phosphate (Firemaster T23P; trade mark). TDl is toluene diisocyanate (809 1 2,4 isomer and 20% 2,6-isomer, by weight). The rise time is expressed in seconds, the density in pounds per cubic foot, the tensile in pounds per square inch, the tear is pounds per linear inch. and the elongation and set in percent. All the properties were determined according to ASTM D-2406-68 procedures.

In each formulation in Table l the polyol. chain extender. catalyst, water. flame retardant and cell modifying agent (siloxane) are first mixed at room tempera ture and then the polyisocyanate is added (also at room temperature) with vigorous stirring; the liquid mixture quickly foams up and solidifies. forming a resilient polyurethane foam.

Table l Onc-Shot Poiyurethane Foam lormulations Pin in lt'ltl ion llltl E\. 5 compound 5 Ex. 1 1 compound 5 MOK'A A 4 Water 3 tr 3.0 3 o Fire retardant 3 t1 lti 3M Cat-aiy ts 1.4 1.4 1.4 Slloxane (H EH15 0.05 l Dl 47 l 4b.| 520 Results Rise ltmc 9U 95 95 Density 1M1 191 1.111 Tensile 19 5 17.48 17.5 Tear To 3.7) 176 Elongation 191 245 215 Lornpression set EXAMPLE 15 This example iliustrates the use of the 3- thydroxyhy drocarbylsecondaryamino )dihydrobenzoiblthiophene l l dioxides as a binary chain extenders for castable solid polyurethanes made from polyes ter-based prepolymers. In this system the prepolymer is first prepared by reacting a predetermined excess of a diisocyanate with a polyester polyol such as polyethylene adipate diol and the resulting prepolymer is reacted with the binary extender at elevated temperatures (e.g.. 70C}. The resultant reaction mixture is then poured into a mold. cared for about 1.5 hours at about 125C and conditioned in air at C and 50% relative humidity for 14 days before testing. This procedure may be followed using as the prepolymer an MDl-polyester (eg. adipic acid-ethylene glycol polyester) prepolymet containing about 6.35? free isocyanate, having an amine equivalent of about 665 and a viscosity at 212F of 1t) poises. and the compound of Example 1 l the binary chain extender.

The prepolymer l gmsl was mixed with the chain extender of Example I l (21 gms) at 70C and poured into two open top 7.5 x 7.5 X (1.1 inch polytetrafluoroethylene tTeflon; trademark) coated molds which were heated and kept at l 10C. The molds were then closed and the cast samples were cured in a heated hydraulic press using contact pressure for 1.5 hours at 115C After cure. the samples were cooled to room temperature. removed from the mold and conditioned in air at C and relati e humidity for 14 days before testing. The physical properties of the solid. rubbery thermoplastic polyurethane were as follows:

[)urometer. Shore =63 Tensile Strength. psi 411(1 Tear Strength. lbslin I 3th S'ttt's .it llltlr l longation. psi 17H "1 Elongauon 560 Optical Propertlcs Transparent Pot Life. minutes 20 using a sample measuring 3 inches by 1 inch which was died out from sheet of stock (1.111 inch thick with a 2 inch slit extending lengthwise from one end. The two legs were put in the jaws of a Scott tester model L and elongated until torn apart. The force required to accomplish this was recorded. The stress at H109? elongation was determined from autographic stressstrain measurements. A (1.10 inch thick sample is died out into a ring. 3 cm. inner diameter. 3.5 cm. outer diameter. placed around pullup rotating at 200 rpm. and elongated at a rate of 10 inches per minute.

EXAMPLE 16 This example further illustrates the preparation of a polyurethane foam made with 3-( 2- hydroxypropylamino) tetrahydro-thiophene 1.1- dioxide (designated CE-1 in Table 11) as the chain extender.

In Table II. the amounts of ingredients are listed in parts by weight; the polyol is the polyether polyol described in Example 14; NEM is Nethylmorpholine. To a 16 ounce paper cup. all of the ingredients in formulation 16 of Table 11 except the TD] were added. This was mixed for approximately 2 minutes and then the TD] added. This combination was then mixed for approximately 10 seconds and poured into a 15 X 15 X 4 inch aluminum mold which was about 1 10F. This was cared for 20 minutes at 250F. and the resultant sample aged 1 week at room temperature before the physical test were run, with the results shown in Table ll.

EXAMPLE 17 Example 17 in Table ll is the same as Example 16 except that the level of the fire retardant T-Z3P was raised from 3 parts to 5 parts.

EXAMPLE 18 EXAMPLE [9 This example was the same as Example 18 except that the T-23P level was increased from 3 to 5 parts.

EXAMPLE 2() This example illustrates the preparation of polyurethane foam made with 3-[ 2- hydroxyethylamino)tetrahydrothiophene l l dioxide as the chain extender. identified as CE-Zt) in Table 11. This example was prepared in the same manner as Example l6.

EXAMPLE 21 This example is the same as Example 21) except that the T-23P level was increased from 3 to 5 parts.

EXAMPLE 22 This example is the same as Example 211 except that instead of using a 1009? TD] system. 1195/5 blend based on equhalents was used of TD] and polymeric MDT (PAPl 901; trademark. polymethylene polyphenylisocyanatc l.

EXAMPLE 2a This example, which is outside the invention, employs MOCA as the chain extender and is included so bon atoms, or a phenyl group,

2 may be hydrogen, an alkyl group having 1 to carbon atoms a phenyl group, or a halogen atom,

R may be (1) an open chain alkylene group having X may be hydrogen, an alkyl group having 1 to 5 carbon atoms or a halogen atom. Y may be hydrogen, an alkyl group having I to 5 carthat it may be used as a comparison between the chain 5 2 to carbon atoms, (2) an open chain alkylene extenders of the invention and a conventionally used group having 2 to 10 carbon atoms in the alkylene chain extender. It was prepared in the same manner as portion substituted with one or more phenyl Example 22. Tear strength and elongation, which are groups, or (3) a cycloalkylene group having 4 to 8 the more important properties for flexible polyurecarbon atoms, thane foams, are superior in the foams made with the 10 the hydroxyl group being attached to a carbon atom chain extenders of the invention, while achieving a deof R that is separated from the secondary amino nisirable value of less than for the compression set. tmgen b at least One Cafb n atom;

TABLE 11 POLYURETHANE FOAMS Material 16 17 1B 19 20 21 22 23 Voranol 4701 100 100 100 100 100 100 100 100 CE-l 5.0 5.0 CE-ll 5.0 5.0 CE-20 5.0 5.0 5.0 MOCA 5.0 Water 3 6 3.6 3.6 3.6 3.6 3.6 3,6 3.6 T-23P 3 0 5.0 3.0 5.0 3.0 5.0 3.0 3.0 Amine Catalysts Dabco 0.50 0.50 0.50 0.50 0.50 0.50 0.60 0.60 NEM 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 Niax 015 0.15 0.15 0.15 0.15 0.15 0.15 0.!5 Tin Catalyst 42 0.03 .0075 DC-ZOO .05 .05 .05 .05 .05 .05 .05 .05 TDl 47.0 47.0 46.1 46.1 47.0 47.0 44.6 40.2 PAPI 901 3.6 0.8 lsocyanate Index 105 105 105 105 105 105 105 105 Tensile 19.75 20.61 17.48 19.06 15.27 14.40 18.74 22.03 Tear 3.60 3.34 2.79 3.06 2.76 3,12 1.94 1.87 Elongation 292 265 245 262 227 212 150 l 39 Compression Set I claim: Formula II: I. In a method of making polyurethanes which com- 40 prises reacting a long chain polyol selected from the group consisting of polyesters, polyethers and polyhy- R1 drocarbons with a chain extender and with a polyisocy- H anate, the improvement which comprises using as chain 2 1 l d R N R 0H extender a 3-(hydroxyhydrocarby secon aryammo) a thiophene 1,1-dioxide of one of the following formulas 1 or 11: 3

R s x Formula I! Y N R 0H wherein X may be as defined in Formula I, R, may be (l) an open chain alkyene group having 2 to 10 carbon atoms, (2) an open chain alkylene 5 group having 2 to 10 carbon atoms in the alkylene i 0 X portion substituted with at least one or more phenyl groups, and (3) a cycloalkylene group having 4 to 8 carbon atoms, the hydroxyl group being attached to a carbon atom of R that is separated from the secondary amino wherein nitrogen atom by at least one carbon atom, and

R, R, R and R are the same or different and are hydrogen, an alkyl group having 1 to 5 carbon atoms, or halogen.

2. A method as in claim 1 in which water is added as an additional reactant, and the resulting polyurethane is a foam. a

3. In a method of making polyurethanes which com prises reacting a long chain polyol selected from the group consisting of polyesters, polyethers and polyhydrocarbons with a chain extender and with a polyisocyanate, the improvement which comprises using as a chain extender a compound as described in claim I, which is a 3- (hydroxyhydrocarbylsecondary amino )tetrahydrothiophene l,l-dioxide of the said Formula I.

4. A method as in claim 3 in which water is added as an additional reactant, and the resulting polyurethane is a foam.

5. A method as in claim 4 in which X, Y and Z are hydrogen and R is an open chain alkylene group having 2 to carbon atoms.

6. A method as in claim 4 in which Y an Z are hydro gen, X is a halogen atom, and R is an open chain alkylene group having 2 to l0 carbon atoms.

7. A method as in claim 4 in which X, Y and Z are hydrogen and R is an open chain alkylene group having 2 to It) carbon atoms substituted with a phenyl group.

8. A method as in claim 4 in which X, Y and Z are hydrogen and R is a cycloalkylne group having 4 to 8 carbon atoms.

9. A method as in claim 4 in which the said chain extender is 3-(2-hydroxypropylamino)tetrahydrothiophene l.l-dioxide.

10. A method as in claim 2 in which the said chain extender is 3-(Z-hydroxypropylamino)-2.3- dihydrobenzo[b] thiophene 1,l-dioxide.

H. A method as in claim 4 in which the said chain extender is 3(Z-hydroxyethylamino)tetahydrothio phene l,l-dioxide.

12. A polyurethane which is a reaction product of a long chain polyol selected from the group consisting of polyesters, polyethers and polyhydrocarbons with a chain extender and with a polyisocyanate, the said chain extender being a compound as described in claim 1.

13. A polyurethane as in claim 12 in which the said chain extender is a compound wherein X, Y and Z are hydrogen and R is an open chain alkylene group having 2 to l0 carbon atoms.

14. A polyurethane as in claim 12 in which the said chain extender is a compound wherein Y and Z are hydroogen. X is a halogen atom, and R is an open chain alkylene group having 2 to l0 carbon atoms.

15. A polyurethane as in claim 12 in which the said chain extender is a compound wherein X, Y and Z are hydrogen and R is an open chain alkylene group having 2 to l0 carbon atoms substituted with a phenyl group.

16. A polyurethane as in claim 12 in which the said chain extender is a compound wherein X, Y and Z are hydrogen and R is a cycloalkylene group having 4 to 8 carbon atoms.

17. A polyurethane as in claim 12 in which the said chain extender is 3-(2-hydroxypropylamino)tetrahydrothiophene l,l-dioxide.

[8. A polyurethane as in claim 12 in which the said chain extender is 3-(Z-hydroxypropylamine)-2.3- dihydrobenzo-lblthiophene l,l-dioxide.

I9. A polyurethane as in claim 12 in which the said chain extender is 3-(2-hydroxyethylamino)tetrahydrothiophene l,l-dioxide.

20. Polyurethane foam made from the reaction products of a polyalkylene polyether polyol having a hydroxylic functionally of at least two, an organic polyisocyanate and a chain extender which is a compouond as described in claim 1.

21. Polyurethane foam as in claim 20 in which the said chain extender is a compound wherein X, Y and Z are hydrogen and R is an open chain alkylene group having 2 to 10 carbon atoms.

22. Polyurethane foam as in claim 20 in which the said claim extender is a compound wherein Y and Z are hydrogen, X is a halogen atom, and R is an open chain alkylene group having 2 to l0 carbon atoms.

23. Polyurethane foam as in claim 20 in which theh said chain extender is a compound wherein X, Y and Z are hydrogen and R is an open chain alkylene group having 2 to l0 carbon atoms substituted with a phenyl group.

24. Polyurethane foam as in claim 20 in which the hydrogen and R is a cycloalkylene group having 4 to 8 carbon atoms.

25. Polyurethane foam as in claim 20 in which the said chain extender is 3-(2- hydroxypropylamine )tetrahydrothiopene l l -dioxide.

26. Polyurethane foam as in claim 20 in which the said chain extender is 3-(Z-hydroxypropylamine)-2,3- dihydrobenzo[b]thiophene l,l-dioxide.

27. Polyurethane foam as in claim 20 in which the said chain extender is 3-(2- hydroxyethylamino)tetrahydrothiophene l, l -dioxide.

28. In a one-shot process for making polyurethane foam wherein a polyalkylene polyether polyol having a hydroylic functionality of at least two, an organic polyisocyanate and a chain extender are simultaneously mixed together, the improvement wherein the siad chain extender is a compound as in claim 1.

29. A one-shot process as in claim 28 in which the said chain extender is a compound wherein X, Y and Z are hydrogen and R is an open chain alkylene group having 2 to l0 carbon atoms.

30. A one-shot process as in claim 28 in which the said chain extender is a compound where Y and Z are hydrogen, X is a halogen atom, and R is an open chain alkylene group having 2 to 10 carbon atoms.

31. A one-shot process as in claim 28 in which the said chain extender is a compound wherein X. Y and Z are hydrogen and R is an open chain alkylene group having 2 to 10 carbon atoms substituted with a phenyl group.

32. A one'shot process as in claim 28 in which the said chain extender is a compound wherein X, Y and Z are hydrogen and R is a cycloalkylene group having 4 to 8 carbon atoms.

33. A one-shot process as in claim 28 in which the said chain extender is 3-( 2- hydroxypropylamino )tetrahydrothiophene l,l-dioxide.

34. A one-shot process as in claim 28 in which the said Chain extender is 3-(Z-hydroxypropylamino)-2,3-

dihydrobenzo[b]thiophene l.l-dioxide.

the 

1. In a method of making polyurethanes which comprises reacting a long chain polyol selected from the group consisting of polyesters, polyethers and polyhydrocarbons with a chain extender and with a polyisocyanate, the improvement which comprises using as chain extender a 3-(hydroxyhydrocarbylsecondaryamino)thiophene 1,1-dioxide of one of The following formulas I or II:
 1. IN A METHOD OF MAKING POLURETHANES WHICH COMPRISES REACTING A LONG CHAIN POLYOL SELECTED FROM THE GROUP CONSISTING OF POLYESTERS, POLYETHERS AND POLYHYDROCARBONS WITH A CHAIN EXTENDER AND WITH A POLYISOCYANATE, THE IMPROVEMENT WHICH COMPRISES USING AS CHAIN EXTENDER A 3(HYDROXYHYDROCARBYLSECONDARYAMINO)THIOPENE 1,1-DIOXIDE OF ONE OF THE FOLLOWING FORMULAS I OR II:
 2. A METHOD AS IN CLAIM 1 IN WHICH WATER IS ADDED AS AN ADDITIONAL REACTION, AND THE RESULTING POLYURETHANE IS A FOAM.
 2. A method as in claim 1 in which water is added as an additional reactant, and the resulting polyurethane is a foam.
 3. In a method of making polyurethanes which comprises reacting a long chain polyol selected from the group consisting of polyesters, polyethers and polyhydrocarbons with a chain extender and with a polyisocyanate, the improvement which comprises using as a chain extender a compound as described in claim 1, which is a 3-(hydroxyhydrocarbylsecondaryamino)tetrahydrothiophene 1,1-dioxide of the said Formula I.
 4. A method as in claim 3 in which water is added as an additional reactant, and the resulting polyurethane is a foam.
 5. A method as in claim 4 in which X, Y and Z are hydrogen and R is an open chain alkylene group having 2 to 10 carbon atoms.
 6. A method as in claim 4 in which Y an Z are hydrogen, X is a halogen atom, and R is an open chain alkylene group having 2 to 10 carbon atoms.
 7. A method as in claim 4 in which X, Y and Z are hydrogen and R is an open chain alkylene group having 2 to 10 carbon atoms substituted with a phenyl group.
 8. A method as in claim 4 in which X, Y and Z are hydrogen and R is a cycloalkylne group having 4 to 8 carbon atoms.
 9. A method as in claim 4 in which the said chain extender is 3-(2-hydroxypropylamino)tetrahydrothiophene 1,1-dioxide.
 10. A method as in claim 2 in which the said chain extender is 3-(2-hydroxypropylamino)-2,3-dihydrobenzo(b) thiophene 1,1-dioxide.
 11. A method as in claim 4 in which the said chain extender is 3-(2-hydroxyethylamino)tetahydrothiophene 1,1-dioxide.
 12. A polyurethane which is a reaction product of a long chain polyol selected from the group consisting of polyesters, polyethers and polyhydrocarbons with a chain extender and with a polyisocyanate, the said chain extender being a compound as described in claim
 1. 13. A polyurethane as in claim 12 in which the said chain extender is a compound wherein X, Y and Z are hydrogen and R is an open chain alkylene group having 2 to 10 carbon atoms.
 14. A polyurethane as in claim 12 in which the said chain extender is a compound wherein Y and Z are hydroogen, X is a halogen atom, and R is an open chain alkylene group having 2 to 10 carbon atoms.
 15. A polyurethane as in claim 12 in Which the said chain extender is a compound wherein X, Y and Z are hydrogen and R is an open chain alkylene group having 2 to 10 carbon atoms substituted with a phenyl group.
 16. A polyurethane as in claim 12 in which the said chain extender is a compound wherein X, Y and Z are hydrogen and R is a cycloalkylene group having 4 to 8 carbon atoms.
 17. A polyurethane as in claim 12 in which the said chain extender is 3-(2-hydroxypropylamino)tetrahydrothiophene 1,1-dioxide.
 18. A polyurethane as in claim 12 in which the said chain extender is 3-(2-hydroxypropylamine)-2,3-dihydrobenzo-(b)thiophene 1,1-dioxide.
 19. A polyurethane as in claim 12 in which the said chain extender is 3-(2-hydroxyethylamino)tetrahydrothiophene 1,1-dioxide.
 20. Polyurethane foam made from the reaction products of a polyalkylene polyether polyol having a hydroxylic functionally of at least two, an organic polyisocyanate and a chain extender which is a compouond as described in claim
 1. 21. Polyurethane foam as in claim 20 in which the said chain extender is a compound wherein X, Y and Z are hydrogen and R is an open chain alkylene group having 2 to 10 carbon atoms.
 22. Polyurethane foam as in claim 20 in which the said claim extender is a compound wherein Y and Z are hydrogen, X is a halogen atom, and R is an open chain alkylene group having 2 to 10 carbon atoms.
 23. Polyurethane foam as in claim 20 in which theh said chain extender is a compound wherein X, Y and Z are hydrogen and R is an open chain alkylene group having 2 to 10 carbon atoms substituted with a phenyl group.
 24. Polyurethane foam as in claim 20 in which the hydrogen and R is a cycloalkylene group having 4 to 8 carbon atoms.
 25. Polyurethane foam as in claim 20 in which the said chain extender is 3-(2-hydroxypropylamine)tetrahydrothiopene 1,1-dioxide.
 26. Polyurethane foam as in claim 20 in which the said chain extender is 3-(2-hydroxypropylamine)-2,3-dihydrobenzo(b)thiophene 1,1-dioxide.
 27. Polyurethane foam as in claim 20 in which the said chain extender is 3-(2-hydroxyethylamino)tetrahydrothiophene 1,1-dioxide.
 28. In a one-shot process for making polyurethane foam wherein a polyalkylene polyether polyol having a hydroylic functionality of at least two, an organic polyisocyanaate and a chain extender are simultaneously mixed together, the improvement wherein the siad chain extender is a compound as in claim
 1. 29. A one-shot process as in claim 28 in which the said chain extender is a compound wherein X, Y and Z are hydrogen and R is an open chain alkylene group having 2 to 10 carbon atoms.
 30. A one-shot process as in claim 28 in which the said chain extender is a compound where Y and Z are hydrogen, X is a halogen atom, and R is an open chain alkylene group having 2 to 10 carbon atoms.
 31. A one-shot process as in claim 28 in which the said chain extender is a compound wherein X, Y and Z are hydrogen and R is an open chain alkylene group having 2 to 10 carbon atoms substituted with a phenyl group.
 32. A one-shot process as in claim 28 in which the said chain extender is a compound wherein X, Y and Z are hydrogen and R is a cycloalkylene group having 4 to 8 carbon atoms.
 33. A one-shot process as in claim 28 in which the said chain extender is 3-(2-hydroxypropylamino)tetrahydrothiophene 1,1-dioxide.
 34. A one-shot process as in claim 28 in which the said chain extender is 3-(2-hydroxypropylamino)-2,3-dihydrobenzo(b)thiophene 1,1-dioxide. 